Most modem air conditioning equipment employ one of several organic solvent compositions, commonly referred to as chlorofluorocarbon compounds (CFCs), as a working fluid (refrigerant). For various reasons, such as wearing of the seals in the air conditioning equipment's compressor, the refrigerant in the equipment may eventually become contaminated with dirt, oil and/or moisture. These contaminants affect the efficiency of the equipment and may eventually lead to damage of the compressor and other components in the equipment. Thus, it is desirable to replace the refrigerant periodically to avoid damaging the equipment and to restore the equipment's overall efficiency. Also, in the event of a failure of the equipment, it is typically required that the refrigerant be removed from the equipment prior to servicing.
Previously, the most common method of removing the refrigerant from the equipment was to vent the refrigerant into the atmosphere and to replace it with virgin refrigerant as required. However, problems exist with this method of removing the refrigerant. The release of CFC compounds into the atmosphere results in the depletion of the ozone layer therein. As the ozone layer is the principal filter in the atmosphere for removing the sun's ultraviolet radiation, much concern has been expressed about its depletion as it is expected to lead to many problems. For example, it is expected that an upturn in related health problems such as skin cancer will occur. Accordingly, many governments are passing legislation restricting or prohibiting the use of and/or releases of CFC compounds into the atmosphere. These restrictions pose a serious problem to refrigeration equipment manufacturers and servicers who no longer can release CFC-type refrigerants into the atmosphere. Another problem in regard of venting of refrigerants to the atmosphere is that the virgin refrigerant compounds required for replacement of vented refrigerants are expensive and may be difficult to obtain.
Refrigerant recovery and recycling systems are described in, for example, U.S. Pat. Nos. 3,699,781; 4,285,206; 4,364,236; 4,805,416; 4,768,347; 4,809,520; 5,072,593; 5,245,840; 5,335,512; 4,809,520; 5,353,603; and 5,617,731.
Most automobile air conditioning units utilize either R-134a refrigerant or R-12 refrigerant. The R-12 refrigerant is often referred to as ozone depleting refrigerant and was commonly used in automobile systems until about the year 1993. Modem automobile systems use the R-134a refrigerant which is more environmentally friendly. Because of the use of different types of refrigerant, it is desirable to provide an apparatus that will recover and recycle each type of refrigerant.